Method and apparatus for creating concrete blocks with the appearance of natural fossil stone

ABSTRACT

A generally conventional concrete block is cast using known procedures. After pouring concrete in a mould, or otherwise forming a block, and before the surface of the concrete has set, shaped bodies of ice are randomly placed on the surface or surfaces to be treated and pressed into the surface(s) to desired depths. The ice bodies will melt during curing of the concrete, but not before the concrete has set enough to keep the shape of the indentations made by the ice bodies. Thus, when the concrete block has set completely, there remains a textured surface having a structure similar to that of natural fossil stone. Alternatively, shaped bodies of combustible material are randomly placed on the surface or surfaces to be treated and pressed into the surface(s) to desired depths. The combustible bodies will make the concrete keep the shape of the indentations made by the bodies after the concrete has cured. After curing, the combustible bodies are heated to their combustion temperature and burned away from the concrete surface. Thus, when the bodies have been removed, there remains a textured surface having a structure similar to that of natural fossil stone.

TECHNICAL FIELD

[0001] The present invention generally relates to the production ofartificial stone, such stone having a surface with randomly dispersedholes making the artificial stone look like a natural fossil rock. Morespecifically, the present invention relates to a method and an apparatusfor producing concrete blocks with the mentioned properties.

BACKGROUND ART

[0002] The manufacture of concrete or concrete blocks is a well-knownconventional process. However, concrete blocks are generally not veryappealing visually, except for decorative architectural blocks.

[0003] Traditionally, imprinting textures onto concrete blocks have beenaccomplished by using compression head stripping shoes with reliefs andtextures formed on the surface, which contacts the concrete block. Thus,as the shoes press down into the concrete, any reliefs or textures aretransmitted to the concrete block surface. The resulting concrete blockis identical to other concrete blocks manufactured with this method, norandomness will be apparent, making a wall off stones appear artificialinstead of natural.

DISCLOSURE OF INVENTION

[0004] It is therefore an object of the invention to provide a method ofproducing an artificial concrete stone having randomly dispersed holesarranged on at least one surface thereof.

[0005] The inventor recognized that there was a need for artificialstone, for load-bearing masonry or non load-bearing masonry, inpredetermined sizing and configurations, for ease of assembly andapplication. The inventor further recognized there was a need for amanufactured stone which could be produced in quantity and at areasonable cost, via a process similar to conventional concrete blockmanufacture, but with additional steps to produce a fossil-likeappearance on one or more sides of the artificial stone. The inventionthus expands the horizons for texture and character into realms notavailable or obtainable with standard and decorative architectural blockprofiles.

[0006] The artificial stone product is created by either filling a mouldwith a typical concrete block aggregate mix or extruding a block usingan extrusion machine. The created concrete block, stone or slab is thenprocessed in one of two preferred embodiments further described below.The moulds or extrusion dies used can be varied greatly, creating abroad spectrum of concrete blocks which can be manufactured using amethod and apparatus according to the invention. Several blocks can bemanufactured simultaneously, by using a multi-compartment mould.

[0007] In a first embodiment of the invention, a generally conventionalconcrete block is provided and frozen water bodies (ice), or bodiesmanufactured from other easily melted materials such as wax, to formindentations in the non-set concrete. After pouring concrete in a mould,or otherwise forming a block, and before the concrete has set, shapedbodies of ice are randomly placed on the surface or surfaces to betreated and pressed into the surface(s) to desired depths. The icebodies will melt during curing of the concrete, but not before theconcrete has set enough to keep the shape of the indentations made bythe ice bodies. Thus, when the concrete block has set completely, thereremains a textured surface having a structure similar to that of naturalfossil stone.

[0008] In a second embodiment of the invention, a generally conventionalconcrete block is cast using combustible bodies to form indentations inthe non-set concrete. After pouring concrete in a mould, or otherwiseforming a block, and before the concrete has set, shaped combustiblebodies of, for example wood, Styrofoam (reg. Trade mark), saw dust,leaves, cardboard, paper, rubber, plastic and hemp etc. are randomlyplaced on the surface or surfaces to be treated and pressed into thesurface(s) to desired depths. The combustible bodies will be burned awayafter curing of the concrete, making the concrete set to keep the shapeof the indentations made by the combustible bodies. Thus, when theconcrete block has set completely, there remains a textured surfacehaving a structure similar to that of natural fossil stone.

[0009] Other aspects and features of the present invention will becomeapparent to those ordinarily skilled in the art upon review of thefollowing description of specific embodiments of the invention inconjunction with the accompanying figures.

BRIEF DESCRIPTION OF DRAWINGS

[0010] Embodiments of the present invention will now be described, byway of example only, with reference to the attached Figures, wherein:

[0011]FIG. 1A is a plan side view of an apparatus for manufacturingconcrete blocks according to the invention;

[0012]FIG. 1B is a plan end view of the apparatus of FIG. 1A;

[0013]FIG. 1C is a flow chart showing the concrete preparation forfeeding into the apparatus of FIGS. 1A and 11B;

[0014]FIG. 1D is a flow chart showing combustion of formed bodiesaccording to the invention;

[0015]FIG. 2 is a perspective view of one embodiment of a mould used inthe apparatus according to the invention;

[0016]FIG. 3 is a perspective view of one embodiment of a compressionmeans used in the apparatus according to the invention;

[0017]FIG. 4 is a plan side view of a first embodiment of a means forspreading formed bodies onto a surface of concrete blocks used in theapparatus according to the invention;

[0018]FIG. 5 is a perspective view of a mould as shown in FIG. 2 when ithas been filled with a concrete mixture;

[0019]FIG. 6 is a perspective view of a first embodiment of a spreadingmeans according to the invention, showing the placing of combustibleformed bodies on top of a mould filled with concrete mixture;

[0020]FIG. 7A is a perspective view of a second embodiment of aspreading means according to the invention, showing the placing ofbodies on top of a mould filled with concrete mixture;

[0021]FIG. 7B is a plan side view of the second embodiment of aspreading means according to the invention, showing the placing ofbodies on top of a mould filled with concrete mixture;

[0022]FIG. 8A is a perspective view of a third embodiment of a spreadingmeans according to the invention, showing the placing of bodies on topof a mould filled with concrete mixture.

[0023]FIG. 8B is a plan side view of the third embodiment of a spreadingmeans according to the invention, showing the placing of bodies on topof a mould filled with concrete mixture;

[0024]FIG. 9 is a perspective view of the pressing means of FIG. 3,shown when used in the apparatus according to the invention for pressingformed bodies into the surface of the concrete mixture in the mould;

[0025]FIG. 10A is a plan side view of the mould as shown in FIGS. 7A and8A, showing the mould after the bodies have been pressed into theconcrete surface;

[0026]FIG. 10B is a plan side view of the mould as shown in FIGS. 7B and8B, showing the concrete blocks removed from the mould after pressing;

[0027]FIG. 11A is a perspective view of the concrete blocks from themould as shown in FIGS. 7A and 8A removed from the mould and ready forfurther processing;

[0028]FIG. 11B is a plan top view of the concrete blocks from the mouldas shown in FIGS. 7B and 8B;

[0029]FIG. 12A is a plan side view of a flame chamber for use in anapparatus according to the invention;

[0030]FIG. 12B is a detail view of a concrete block having combustiblebodies pressed into its surface;

[0031]FIG. 12C is a detail view of a concrete block having combustiblebodies burned away leaving voids in its surface; and

[0032]FIG. 12D is a perspective view of the flame chamber of FIG. 12A.

BEST MODE FOR CARRYING OUT THE INVENTION

[0033] The manufacture of concrete takes many forms, but the basis is tointroduce powdered cement, by a volume of 10 to 20 percent, to anaggregate of sand, limestone and water. The size and gradation of theaggregate can vary greatly depending on the process, but the end resultdesired is to have the cement bind the aggregate together through theprocess of hydration to achieve a solid state. Color pigments,plasticizers, water repellents, accelerators/retarders may also be addedto customise the cast concrete properties. The concrete can be in asemi-liquid state, for instance like Redi-Mix™ Concrete, which requiresa form or mould to contain and shape the concrete until it is hard. Dryconcrete, called “zero slump” can be used in the process, utilizing asingle mould box, which is used over and over again to form the concreteblocks. The dry product is formed in the mould up to ten cycles perminute. The thus formed product remains stable in size and shape afterrelease from the mould until final cure. Curing can take place by usualmeans, without introduction of steam and heat to accelerate curing whenusing Redi-Mix, or inside chambers using steam and heat when using “zeroslump” concrete to accelerate the curing process. FIG. 1A shows oneembodiment of a casting machine 1 according to the invention. A hopper14 of the machine is fed from a mixing station 10, which is shown inschematic form in FIG. 1C. The casting machine 1 further has a mold 12and a compression head 13. The aggregate mix contained in the hopper isdischarged to a feed-box 15. The feed-box carries a proportioned amountof aggregate over the mold 12, the mold being arranged lower than thefeed-box at this time. A pallet 16 is held tightly against the cavitiesin the mold and the compression head is held away from the mold, toallow the feed-box unrestricted access to the mold, for depositingaggregate into the cavities of the mold.

[0034] Installed on the front of the feed-box is a cut-off bar 17, thatstrikes off and levels the aggregate in the mold prior to compaction bythe compression head. Also mounted on the top of the cut-off bar is abristle sweeper bar 18, that cleans off the stripper shoes on thecompression head. This occurs as the cut-off bar 17 passes back andforth under the compression head while aggregate fills the cavities 12′of the mold. After the cut-off bar 17 has returned to it's home positionunder the hopper 14, the compression head 13 is lowered into theaggregate in the cavities of the mold 12. The compression head hasplates 13′ mounted to it having the same general shape as the cavitiesin the mold, and the plates compress the aggregate in the mold tospecified densities. These plates are called stripper shoes, and aretraditionally available in an extensive range of patterns for stampingtheir pattern onto the aggregate in the mold (this is not the case inthe present invention).

[0035] During this process the compression head 13 and the mold 12receive intense vibration to consolidate the aggregate in the moldcavities, and assist with compaction of the concrete block unit beingmade.

[0036] To cast the concrete block according to the invention, apreferred mix of crushed limestone and manufactured sand is used. Twoadditives are optionally introduced to obtain plasticity and waterrepellence, and colour is introduced into the aggregates to reproducethe colours of natural stone. Water and concrete are added to complete atypical preferred mix as follows: 2,000 lb. Manufactured concrete sand2,000 lb. Crushed limestone screenings 50 oz. Water repellent additive400 lb. Cement powder 16 oz. Plasticizer 14 lb. Iron oxide color pigmentWater To required volume

[0037] The products are blended to form a zero-slump concrete mix thatis introduced into moulds of various sizes and shapes for the initialproduct. The typical sizes are defined by widths of 10 cm (4″), 15 cm.(6″), 20 cm. (8″), 25 cm. (10″) and 30 cm. (12″), in varying lengths andthicknesses. The products are advantageously manufactured in specialconfigurations to allow solid material for fracturing in random lengths.The product is promptly removed from the moulds and is then fully curedin chambers with live steam, heat and 100% humidity. These factorsachieve concrete hydration and binding of the material. This process istypical for conventional manufacturing of concrete blocks and theircuring process.

[0038] According to a first embodiment of the invention, to form thedesired impressions in the concrete surface, formed bodies of ice, orother meltable material (i.e. material that melts at temperatures aroundroom temperature, 20 deg. Celsius), are pressed into the surface andleft there when the block is moved to a curing facility. During curing,the ice bodies will melt, leaving the desired impression in the concretesurface. The surface may be on a horizontal or a vertical plane of thefinished concrete block in its application, as desired, or on more thanone surface, for instance for corner applications. By controlling thesizes, shapes and quantity of ice bodies applied to the concretesurface, it is possible to achieve a natural fossil stone look of thetreated surface having a “random” dispersement of different size andshape indentations. The ice bodies are preferably hard frozen, i.e. havea temperature well below the freezing point of water, to prolong theperiod of time they stay hard when pressed into the soft concretesurface. The supply of appropriate formed ice bodies may be critical foran automated manufacturing plant, thus a fast-freezing mass productionof ice bodies may be necessary. To achieve a natural looking artificialfossil stone, the ice body shape/size mix and quantity must beestablished.

[0039] The application of the ice bodies may be manual or automatic.Manual application can be anything from placing and pressing each icebody separately on and into the concrete surface, to spreading out theice body contents of a container onto the concrete surface and pressingall bodies down using a manual or automatic press. Automatic applicationis preferably performed similar to the last described manualapplication, but preferably using an automatic press only. For instance,concrete slabs coming from an automatic concrete extrusion machine maybe held in a mould box, or equivalent structure, and have one or moresurfaces treated automatically or manually as per above. Alternatively,concrete blocks cast individually may be manually or automaticallytreated with ice bodies whilst still in the mould.

[0040] The Fossil Stone appearance of the invention is created duringthis manufacturing process with the following functions. During theprocedures noted above, and after the cut-off bar 17 has returned toit's home position under hopper 14, but prior to the compression head 13lowering onto the aggregate in the cavities of the mold 12, ice bodies,for instance of sizes from 0.25 inch (6.35 mm) to 2.50 inches (63.5 mm)in diameter and from 0.50 inch (12.7 mm) to 4.00 inches (101.6 mm) inlength, are dispensed over the aggregate in the mold. The ice bodies areplaced over the aggregate in the mold by either controlled distribution(FIG. 6) or random distribution (FIG. 7) prior to the compression head13 lowering down, and are subsequently compressed into the surface areasof the concrete block units after the compression head 13 has loweredinto the mold (see FIG. 9).

[0041] The above process creates a conventional concrete clock in anextensive range of sizes dependant on the mold being used and it'sconfiguration. The size, shape and hardness of the Ice bodies iscritical to realize accurate representation of the Fossil Stoneappearance, and it is extremely important to ensure consistentdistribution of the ice bodies is realized without fusion, melting orfracture during the process. There are two means for distribution of theice bodies onto the aggregate in the mold, one creating a “ControlledDistribution” and one creating a Random Distribution”. The “ControlledDistribution” is realized by introduction of the ice bodies on aconveyor belt 20 the width of the mold 12, and as the conveyor belttravels over the top of the mold, the ice bodies 21 fall off the frontonto the mold. Following the retraction of the conveyor belt 20 is anice rake 22 with a series of, for instance six inches (152.4 mm) long,wires 23, for example one inch (25.4 mm) apart. The ice rakeadvantageously vibrates as it sweeps over the top of the mold and theice bodies 21, equally distributing the ice bodies over the mold.

[0042] The “random Distribution” is realized from blowing the ice bodies21 through a hose 24 with air as the means of forcing the ice bodiesthrough the hose. The hose oscillates sideways back and forth until thedesired amount of ice bodies are dispensed. There is no secondary meansof leveling the ice bodies as the random application creates the desiredresult.

[0043] Alternatively, the ice body distribution can also be providedboth in Consistent and Random Distributions by means of an auger 25. Theauger moves both horizontally and vertically over the mold 12 and augersthe ice bodies onto the aggregate.

[0044] Once the ice bodies 21 are dispensed over the aggregate in themold 12, the compression head 13 is lowered forcing the ice bodies intothe surface areas of the aggregate. Continuous vibration occurs duringthis phase, until the contact points (between compression head and mold)are reached defining the proper height on the concrete block units. Atthis point the vibration of the compression head and the mold ends andthe concrete block units are discharged from the mold.

[0045] The newly manufactured concrete block units with ice bodiesembedded in the surface areas are transported on a manufacturing pallet16 to the curing chambers (not shown). During the curing process, theice bodies 21 melt leaving voids 27 in the surface of the concrete blockunits the same shapes as the frozen ice bodies that were embedded in theproduct earlier.

[0046] After final cure, the concrete block units are removed from thecuring chambers on the manufacturing pallets 16 to a work station (notshown) where the concrete block units are clamped and removed to a cube(not shown) that is wrapped and bound for inventory until delivery tothe job-site.

[0047] Typical steps for an automated concrete block process would be:

[0048] a) Providing a steel mould of the desired concrete block outershape;

[0049] b) Filling the mould with a pre-determined amount of softaggregate mix;

[0050] c) Compressing the material in the mould to a desired heightwithin the mould;

[0051] d) Introducing ice bodies onto a desired surface of the concretematerial still in the mould;

[0052] e) Pressing the ice bodies down to a desired depth in theconcrete surface;

[0053] f) Removing the pressed concrete block, which has sufficientgreen strength to keep its shape, the ice bodies are still pressed intothe treated surface; and

[0054] g) Curing the pressed concrete block.

[0055] After introducing the ice bodies in step d) it is advantageous tolevel off the layer of deposited ice bodies, for example by using aswipe plate, finger plate or ice rake, prior to pressing the ice bodiesdown into the concrete surface.

[0056] Curing can be done either by leaving the block at ambienttemperature for the desired period of time, or by treating it with steamand/or heat from other sources. The ice bodies will thus not melt untilthe curing starts.

[0057] Alternatively, the application of the ice bodies may be donebefore step c) so that the ice bodies will be pressed into the concretesurface during the compression of the material in the mould to a desiredheight within the mould. The method steps would then be:

[0058] a) Providing a steel mould of the desired concrete block outershape;

[0059] b) Filling the mould with a pre-determined amount of softaggregate mix;

[0060] c) Introducing ice bodies onto a desired surface of the concretematerial still in the mould;

[0061] d) Compressing the material in the mould to a desired heightwithin the mould and simultaneously pressing the ice bodies down to adesired depth in the concrete surface;

[0062] e) Removing the pressed concrete block, which has sufficientgreen strength to keep its shape, the ice bodies are still pressed intothe treated surface; and

[0063] f) Curing the pressed concrete block.

[0064] When using a concrete slab, the method steps would be:

[0065] a) Providing a formed concrete slab of the desired shape;

[0066] b) Placing said slab in a holder or form, defining the slab form;

[0067] c) Introducing ice bodies onto a desired surface of said slab;

[0068] d) Pressing said ice bodies down to a desired depth in saidsurface;

[0069] e) Removing the holder after the initial cure of the slab, theice bodies still being pressed into the treated surface; and

[0070] f) Final curing of the concrete slab.

[0071] Other materials are suitable to form the bodies, apart from ice.Thus, wax or similar material can be used, provided the material meltsat low temperatures (for example temperatures close to room temperature,20° C.), but the ice bodies were superior to all tested materials. Theice is cheap and very easy to repeatedly form into the desired shapes,and does not pollute the environment. Furthermore, no extra heatingstep, further to any heat curing of the concrete, is necessary whenusing ice. If wax is used, a separate step has to be performed, in whichthe temperature of the treated concrete block surface is raised abovethe melting temperature of the wax material.

[0072] According to a second embodiment of the invention, to form thedesired impressions in the concrete surface, combustible formed bodies21′ are pressed into the surface and left there when the block is movedto a curing facility. Preferable materials used for the combustiblebodies are different types of wood or pressed and glued wood chips,paper, plastic, Styrofoam (reg. Trade mark), saw dust, leaves,cardboard, rubber and hemp etc. It is also envisioned to use anycombination of bodies made of different material, as long as the bodyitself can be removed from the cured concrete block using heat. Forexample, ice bodies may be used in combination with combustible bodies.During curing, the ice bodies will melt, leaving the desired impressionin the concrete surface. After curing, any combustible bodies will beheated to at least their combustion temperature, for example in a flamechamber 100 as shown in FIGS. 12A to 12D, to burn away the combustiblebodies and leave the indentations they formed visible in the concretesurface. FIG. 12B shows a concrete block before the combustible bodies21′ have been burned away, and FIG. 12C shows the concrete block afterthe combustible bodies are burned away leaving voids 27′ in the concretesurface. The flame chamber houses at least one burner 110, which directsa flame 120 towards the surface of the concrete block to be treated. Thetreated concrete surface may be on a horizontal or a vertical plane ofthe finished concrete block, in its application, as desired, or on morethan one surface, for instance for corner applications. By controllingthe sizes, shapes and quantity of the bodies applied to the concretesurface, it is possible to achieve a natural fossil stone look of thetreated surface having a “random” dispersement of different size andshape indentations. The supply of appropriate formed ice bodies may becritical for an automated manufacturing plant, thus a fast-freezing massproduction of ice bodies may be necessary. To achieve a natural lookingartificial fossil stone, the body shape/size mix and quantity must beestablished.

[0073] The application of the bodies may again be manual or automatic,and is essentially performed in the same way as earlier described forice bodies. Manual application can be anything from placing and pressingeach body separately on and into the concrete surface, to spreading outthe body contents of a container onto the concrete surface and pressingall bodies down using a manual or automatic press. Automatic applicationis preferably performed similar to the last described manualapplication, but preferably using an automatic press only. For instance,concrete slabs coming from an automatic concrete extrusion machine maybe held in a mould box, or equivalent structure, and have one or moresurfaces treated automatically or manually as per above. Alternatively,concrete blocks cast individually may be manually or automaticallytreated with bodies whilst still in the mould.

[0074] Typical steps for an automated concrete block process would be:

[0075] a) Providing a steel mould of the desired concrete block outershape;

[0076] b) Filling the mould with a pre-determined amount of softaggregate mix;

[0077] c) Compressing the material in the mould to a desired heightwithin the mould;

[0078] d) Introducing combustible bodies onto a desired surface of theconcrete material still in the mould;

[0079] e) Pressing the combustible bodies down to a desired depth in theconcrete surface;

[0080] f) Removing the pressed concrete block, which has sufficientgreen strength to keep its shape, the combustible bodies are stillpressed into the treated surface;

[0081] g) Curing the pressed concrete block; and

[0082] h) Heating the combustible bodies to their combustiontemperature, to burn away the combustible bodies from the cured andpressed concrete block.

[0083] After introducing the bodies in step d) it is advantageous tolevel off the layer of deposited combustible bodies, for example byusing a swipe plate, finger plate or ice rake, prior to pressing thebodies down into the concrete surface.

[0084] Curing can be done either by leaving the block at ambienttemperature for the desired period of time, or by treating it with steamand/or heat from other sources. Any ice bodies will thus not melt untilthe curing starts.

[0085] Alternatively, the application of the combustible bodies may bedone before step c) so that the combustible bodies will be pressed intothe concrete surface during the compression of the material in'the mouldto a desired height within the mould. The method steps would then be:

[0086] a) Providing a steel mould of the desired concrete block outershape;

[0087] b) Filling the mould with a pre-determined amount of softaggregate mix;

[0088] c) Introducing combustible bodies onto a desired surface of theconcrete material still in the mould;

[0089] d) Compressing the material in the mould to a desired heightwithin the mould and simultaneously pressing the combustible bodies downto a desired depth in the concrete surface;

[0090] e) Removing the pressed concrete block, which has sufficientgreen strength to keep its shape, the combustible bodies are stillpressed into the treated surface;

[0091] f) Curing the pressed concrete block; and

[0092] g) Heating the combustible bodies to their combustiontemperature, to bum away the combustible bodies from the cured andpressed concrete block.

[0093] When using a concrete slab, the method steps would be:

[0094] a) Providing a formed concrete slab of the desired shape;

[0095] b) Placing the slab in a holder or form;

[0096] c) Introducing combustible bodies onto a desired surface of theslab;

[0097] d) Pressing the combustible bodies down to a desired depth in thesurface;

[0098] e) Removing the holder after the initial cure of the cement slab,the combustible bodies still being pressed into the treated surface;

[0099] f) Final curing of the concrete block; and

[0100] g) Heating the combustible bodies to their combustiontemperature, to burn away the combustible bodies from the cured andpressed concrete slab.

[0101] It will be appreciated that the above description relates to thepreferred embodiments by way of example only. Many variations on theinvention will be obvious to those knowledgeable in the field, and suchobvious variations are within the scope of the invention as describedand claimed whether or not expressly described. For instance, it hasbeen mentioned that a mixture of meltable and combustible bodies can beused. The meltable bodies would then melt during the combustion of thecombustible bodies. A reason for mixing different material bodies isthat some shapes are easier to make using a certain material, or can befound in nature already formed, and other shapes are cheapest andeasiest formed using ice as mentioned earlier.

[0102] It should also be understood that the invention is not restrictedto the specific concrete mix mentioned above, the process beingadaptable to almost any typical mix design for manufactured products,nor are the preferred additives essential, although they are desirable.

INDUSTRIAL APPLICABILITY

[0103] The invention provides a method of producing artificial stone,such as concrete blocks, having a surface with randomly dispersed holesmaking the artificial stone look like a natural fossil rock to be usedfor building purposes.

1. A method of producing surface textured concrete blocks, comprisingthe steps of: a) Providing an un-cured concrete block of apre-determined outer shape; b) Introducing formed bodies onto a desiredsurface of said concrete block; c) Pressing said formed bodies down to adesired depth in said surface; d) Removing the pressed concrete block,which has sufficient green strength to keep its shape, said formedbodies still pressed into said surface; and e) At least partly curingsaid pressed concrete block; f) Removing said formed bodies.
 2. Themethod as recited in claim 1, further comprising the step of levelingoff the layer of deposited ice bodies, by raking the ice bodies, afterintroducing the formed bodies in step b) and prior to step c).
 3. Themethod as recited in claim 1, where said formed bodies are manufacturedfrom a meltable material and step f) comprises heating said at leastpartly cured concrete block to a temperature at which said formed bodiesmelt and are removed from said concrete block.
 4. The method as recitedin claim 3, where the material of said formed bodies is chosen from anyof the group comprising ice and wax.
 5. The method as recited in claim1, where said formed bodies are manufactured from a combustible materialand step f) comprises heating said at least partly cured concrete blockto a temperature at which said formed bodies combust and are removedfrom said concrete block.
 6. The method as recited in claim 5, where thematerial of said formed bodies is chosen from any of the groupcomprising wood, saw dust, leaves, cardboard, paper, rubber, plastic andhemp.
 7. The method as recited in claim 1, where step a) comprisesproviding a mould of the desired concrete block outer shape and fillingsaid mould with a pre-determined amount of soft aggregate material mix.8. The method as recited in claim 7, further comprising the step ofcompressing said material in said mould to a desired height within saidmould after step a) and before step b).
 9. The method as recited inclaim 7, where step c) further comprises compressing said material insaid mould to a desired height within said mould.
 10. The method asrecited in claim 1, where step a) comprises providing an extrudedconcrete block of the desired shape and placing said concrete block in aholder.